Interpretation

Theoretical Background

According to Strahler (1983), the shape of land is the land surface configuration generated by natural processes. Further Whitton (1984) stated that the land forms a morphology and surface characteristics of land as a result of interaction between physical processes and crustal movements by coating the surface of the earth's geology. Under the second definition, it can be concluded that the shape of the land is part of the earth's surface that has a distinctive topographic forms, due to the strong influence of natural processes and geological structures in the rock material in a specific chronological time and space. Or it can also be said that the landform is formed on the surface of the earth as a result of changes in the form of the earth's surface by geomorphic processes operating in the earth's surface. Each landform is characterized by the differences in terms of structure and process geomorphology, relief/topography, and the constituent material (lithology).
Geomorphological structure provides information about the origin (genesis) of the land form. Geomorphological processes mirrored by the level erosion, while the relief is determined by the difference in the highest point with the lowest point and slope. Relief or topography gives the impression of information about the configuration of the surface shape is determined by the state land morphometric. Lithological information types and characteristics of rocks and their constituent minerals, which would affect the formation of landforms.
By looking at very complex the landscape that is in the earth's surface, it must first be classified into landform units. Thus, the classification of landform aims to simplify a complex landscape in the earth's surface into simple units (of land) that have a similarity in the nature.
Verstappen (1983) has classified based on landform genesis into ten main classes, namely:

1. Structural landform origin.
2. Volcanic landform origin.
3. Denudational landform origin.
4. Fluvial landform origin.
5. Marine landform origin.
6. Glacial landform origin.
7. Aeolian landform origin.
8. Solusional landform origin.
9. Organic landform origin.
10. Anthropogenic landform origin.

The earth’s surface composes three rocks types: igneous, sedimentary and metamorphic rocks. Each type of the rocks has a certain characteriristic that is reflected in the relief, topography, drainage pattern, drainage density, the landform and land cover/land use.
Constituent aspects of landform units, rock type and geological structure can be identified from photo or image characteristics such as: tone or color, mottling, texture, pattern, shape, size, shadow, site and geographical situation, which are then carried out field checks. Interpretation of aerial photos will provide an overview geomorphological processes such as erosion, sedimentation, weathering, and rock mass movement. The rocks types and the geological structures data or information can be used as basic data for the other thematic maps construction, such hydrogeomorphologic, morphoconservation and soil maps. Both rock types and geological structures are important factors for land evaluation, hazard assessment as input data for regional planning.

Aim of the exercise
1. to identify the rock types from landsat image
2. to identify geological structure from landsat image
3. to identify the landform unit from landsat image
4. to analyze spatial distribution of the rock type, geological structure and landform unit in relation to landuse or land cover.


CHAPTER II
METHOD

Material and equipments
1. Landsat TM 5 Composite Band 457 Kendal-Temanggung and Surrounding Area, Central Java
2. Topographical maps, Geological maps
3. Computer

Procedure
1. Delineation of the drainage pattern
2. Delineation of the relief or morphology
3. The analysis of the vegetation and land use
4. Analysis of the rocks type (lithology) and its structures
5. Deliniation of the lithological unit and draw the geological structure
6. Deliniation the landform unit
7. Identify geomorphic processes



Analysis of the lithological, geological structure, and landform unit based on Land Unit

River Delta
Locate of this area is in coastal area and flat relief area. This is an outlet of river. This area has dark red color, it shows that the area has high density vegetation, and it is possible that the vegetation is mangrove because locate in coastal area. Red color shows vegetation object in the satellite images with 457 composite bands. Fine texture shows that the type of rock in this area is alluvium, result of sedimentation from upper area. Because the process of this area be influenced by sedimentation that is transported by river, so the geomorphic process is fluvial landform.

Fluvial Marine Plain
This area is in flat relief area. In the past time, this area is a river delta, it is proven by pattern of this area like a fan. There is a accumulation place of sediment that is transported by river. So in the past, geomorphic process of this area is fluvial marine. But now the geomorphic process of this area is fluvial landform. Because it has many sediment of river transport that deposite on this area and the soil type is alluvium. In image is appeared with fine texture. The landuse of this area is rice field with red color and regular pattern, like rectangle. Vegetation is seen by red color in image. The drainage pattern in this area is meandering. It shows that the area has located in lower part of fluvial system.

Alluvial Plain
This area is in flat area and associate with meandering drainage pattern. The meandering drainage pattern shows that the area has fine texture of soil. It is possible that the soil is alluvium. Differ with fluvial marine plain, this area has green color. It shows that the area has low density vegetation. Green color shows soil object in the satellite images with 457 composite bands. Low density vegetation shows landuse in this area is not rice field or rice field but not planted. This is a tight area with hilly area on the surrounding area.
Fluvial Volcanic Plain
This area is in sloping relief area. The drainage pattern in this area is meandering. The meandering drainage pattern shows that the area has fine texture of rock. It is possible that the rocktype is tuff, because this area still be influenced by volcanic geomorphic process. Color of this area is green, it shows that vegetation in this area is low density and maybe the landuse is dry field. In some place of this area, there are several object which have dark blue color. The object is the water surface and It is possible that the landuse is pond.

Foot Volcanic Plain
This area is rolling relief area. Drainage pattern in this area is dendritic. The dendritic drainage pattern shows that this area is in upper land. The texture in this area is medium texture, it shows the rocktype in this area is medium texture. It is possible that the rocktype is tuff, because this area still be influenced by volcanic geomorphic process. Color of this area is orange and green color. Orange and green color show that this area has various landuse, maybe forest, dryfield, or open land. But many places in this area have dark blue color. The object is the water surface and it is possible that the landuse is pond.

Lower Volcanic Slope
This area is in hilly relief area. Drainage pattern in this area is dendritic. The dendritic drainage pattern shows that this area is in upper land. The texture in this area is almost coarse texture, it shows the rock type in this area is coarse texture. It is possible that the rock type is breccia, because this area still be influenced by volcanic geomorphic process. Color of this area is orange color. It shows that the area is dominated with medium density vegetation. This area has straight pattern that likely valley. It shows that erosion process in this area is high.

Middle Volcanic Slope
This area is in hilly-steeply relief area. Drainage pattern in this area is parallel. The type of this drainage is consequen. It is drainage that has direction same with direction of slope. The texture in this area is almost coarse texture, it shows the rock type in this area is coarse texture. It is possible that the rock type is breccia, because this area still be influenced by volcanic geomorphic process. Color of this area is orange and young green color. Orange and green color shows that this area has various landuse, maybe forest or orchad with various density of vegetation. There are high density and medium density vegetation.

Upper Volcanic Slope
This area is in steeply relief area. Drainage pattern in this area is radial sentrifugal. Drainage forms radial pattern from a peak to lower part sentrifugally. The type of this drainage is consequen. It is drainage that has direction same with direction of slope. The texture in this area is almost coarse texture, it shows the rocktype in this area is coarse texture. It is possible that the rocktype is andesite, because this area is near with peak of volcanic mountain. Color of this area is young green color. Young green color shows that this area has low density vegetation. It is possible that landuse is ochard.

Volcanic Cone
This area is in mountainous relief area. Drainage pattern in this area is radial sentrifugal. Drainage forms radial pattern from a peak to lower part sentrifugally. This area has conical pattern, it shows that this area is a peak of volcanic mountainous. The type of this drainage is consequen. It is drainage that has direction same with direction of slope. The texture in this area is almost coarse texture, it shows the rocktype in this area is coarse texture. It is possible that the rocktype is andesite, because this area is a peak of volcanic mountain. Color of this area is young green color. Young green color shows that this area has low density vegetation. It is possible that landuse is open land.

High Eroded Denudational Hill
This area is in hilly relief area. The drainage pattern in this area is irregular pattern. The density of drainage pattern is high, it shows that this area has fine texture of rock type. It is possible that the rock type is breccia, because this area still be influenced by volcanic geomorphic process. The rock with fine texture and inresistant material made this area became to be eroded. The erosion happened with high scale. It can be seen with the irregular pattern of crest. This area has orange color, it shows that the landuse is forest with high density vegetation.

Medium Eroded Denudational Hill
Same with high eroded denudational hill, this area is in hilly relief area, but the drainage pattern in this area is dendritic pattern. The density of drainage pattern is almost high, it shows that this area has fine texture of rock type. It is possible that the rock type is breccia, because this area still be influenced by volcanic geomorphic process. The rock with fine texture and inresistant material made this area became to be eroded. The erosion happened with medium to high scale. It can be seen with the irregular pattern of crest. This area has orange color, it shows that the landuse is forest with high density vegetation.

Low Eroded Denudational Hill
This area is in hilly-steeply relief area with drainage pattern in this area is irregular pattern. The density of drainage pattern is medium, it shows that this area has almost fine texture of rock type. It is possible that the rock type is breccia, because this area still be influenced by volcanic geomorphic process. The rock with fine texture and inresistant material made this area became to be eroded. But differ with the other denudational hill, the erosion happened with low scale. It can be seen with the regular pattern of crest but almost to irregular pattern. This area has orange color, it shows that the landuse is forest with high density vegetation.


Natural resources in landform unit

Fluvial landform has soil type that contains organic matter. It make the soil became to fertile. It seen with the landuse in fluvial landform area is dominated by agricultural land. And in structural and denudational landform is dominated by forestry land. Agricultural and forestry aspect in this area can became to be resourced to increase regional economics.


Natural hazzard potency in landform unit

This area is dominated by hilly relief formation. With the texture of coarse rock which was dominated by sand, so it is possible to be an area prone to landslides. Especially in areas with the formation of denudational landforms. For that, we need the existence of a spatial planning that takes into account vulnerability to disasters, such as not make a planning to build settlement in high vulnerable areas of landslides disaster. In addition, the potential for lowland flooding. That's because the many rivers that flow and leads to the alluvial plains. Those rivers carry water from higher land. For that, we need the a plan regarding drainage to prevent flooding disasters that may occur.


REFERENCE


Ramadhani, Adi. 2008. Laporan Praktikum Penginderaan Jauh untuk Litosfer. Yogyakarta: Faculty of Geography, GMU
Ramadhani, Adi. 2008. Laporan Praktikum Analisis Medan. Yogyakarta: Faculty of Geography, GMU
Van Zuidam, R. A. and Van Zuidam-Cancelado. 1979. Terrain analysis and classification using aerial photographs. ITC Textbook of photo-interpretation, VII-6.